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GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/proof/proof_node_manager.cpp	Lines:	180	219	82.2 %
Date:	2021-11-05	Branches:	287	892	32.2 %


/******************************************************************************
 * Top contributors (to current version):
 *   Andrew Reynolds, Haniel Barbosa, Aina Niemetz
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
 * in the top-level source directory and their institutional affiliations.
 * All rights reserved.  See the file COPYING in the top-level source
 * directory for licensing information.
 * ****************************************************************************
 *
 * Implementation of proof node manager.
 */

#include "proof/proof_node_manager.h"

#include <sstream>

#include "options/proof_options.h"
#include "proof/proof.h"
#include "proof/proof_checker.h"
#include "proof/proof_node.h"
#include "proof/proof_node_algorithm.h"
#include "theory/rewriter.h"

using namespace cvc5::kind;

namespace cvc5 {

ProofNodeManager::ProofNodeManager(theory::Rewriter* rr, ProofChecker* pc)
    : d_rewriter(rr), d_checker(pc)
{
  d_true = NodeManager::currentNM()->mkConst(true);
  // we always allocate a proof checker, regardless of the proof checking mode
  Assert(d_checker != nullptr);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkNode(
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    Node expected)
{
  Trace("pnm") << "ProofNodeManager::mkNode " << id << " {" << expected.getId()
               << "} " << expected << "\n";
  bool didCheck = false;
  Node res = checkInternal(id, children, args, expected, didCheck);
  if (res.isNull())
  {
    // if it was invalid, then we return the null node
    return nullptr;
  }
  // otherwise construct the proof node and set its proven field
  std::shared_ptr<ProofNode> pn =
      std::make_shared<ProofNode>(id, children, args);
  pn->d_proven = res;
  pn->d_provenChecked = didCheck;
  return pn;
}

std::shared_ptr<ProofNode> ProofNodeManager::mkAssume(Node fact)
{
  Assert(!fact.isNull());
  Assert(fact.getType().isBoolean());
  return mkNode(PfRule::ASSUME, {}, {fact}, fact);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkSymm(
    std::shared_ptr<ProofNode> child, Node expected)
{
  if (child->getRule() == PfRule::SYMM)
  {
    Assert(expected.isNull()
           || child->getChildren()[0]->getResult() == expected);
    return child->getChildren()[0];
  }
  return mkNode(PfRule::SYMM, {child}, {}, expected);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkTrans(
    const std::vector<std::shared_ptr<ProofNode>>& children, Node expected)
{
  Assert(!children.empty());
  if (children.size() == 1)
  {
    Assert(expected.isNull() || children[0]->getResult() == expected);
    return children[0];
  }
  return mkNode(PfRule::TRANS, children, {}, expected);
}

std::shared_ptr<ProofNode> ProofNodeManager::mkScope(
    std::shared_ptr<ProofNode> pf,
    std::vector<Node>& assumps,
    bool ensureClosed,
    bool doMinimize,
    Node expected)
{
  if (!ensureClosed)
  {
    return mkNode(PfRule::SCOPE, {pf}, assumps, expected);
  }
  Trace("pnm-scope") << "ProofNodeManager::mkScope " << assumps << std::endl;
  // we first ensure the assumptions are flattened
  std::unordered_set<Node> ac{assumps.begin(), assumps.end()};
  // map from the rewritten form of assumptions to the original. This is only
  // computed in the rare case when we need rewriting to match the
  // assumptions. An example of this is for Boolean constant equalities in
  // scoped proofs from the proof equality engine.
  std::unordered_map<Node, Node> acr;
  // whether we have compute the map above
  bool computedAcr = false;

  // The free assumptions of the proof
  std::map<Node, std::vector<std::shared_ptr<ProofNode>>> famap;
  expr::getFreeAssumptionsMap(pf, famap);
  std::unordered_set<Node> acu;
  for (const std::pair<const Node, std::vector<std::shared_ptr<ProofNode>>>&
           fa : famap)
  {
    Node a = fa.first;
    if (ac.find(a) != ac.end())
    {
      // already covered by an assumption
      acu.insert(a);
      continue;
    }
    // trivial assumption
    if (a == d_true)
    {
      Trace("pnm-scope") << "- justify trivial True assumption\n";
      for (std::shared_ptr<ProofNode> pfs : fa.second)
      {
        Assert(pfs->getResult() == a);
        updateNode(pfs.get(), PfRule::MACRO_SR_PRED_INTRO, {}, {a});
      }
      Trace("pnm-scope") << "...finished" << std::endl;
      acu.insert(a);
      continue;
    }
    Trace("pnm-scope") << "- try matching free assumption " << a << "\n";
    // otherwise it may be due to symmetry?
    Node aeqSym = CDProof::getSymmFact(a);
    Trace("pnm-scope") << "  - try sym " << aeqSym << "\n";
    Node aMatch;
    if (!aeqSym.isNull() && ac.count(aeqSym))
    {
      Trace("pnm-scope") << "- reorient assumption " << aeqSym << " via " << a
                         << " for " << fa.second.size() << " proof nodes"
                         << std::endl;
      aMatch = aeqSym;
    }
    else
    {
      // Otherwise, may be derivable by rewriting. Note this is used in
      // ensuring that proofs from the proof equality engine that involve
      // equality with Boolean constants are closed.
      if (!computedAcr)
      {
        computedAcr = true;
        for (const Node& acc : ac)
        {
          Node accr = d_rewriter->rewrite(acc);
          if (accr != acc)
          {
            acr[accr] = acc;
          }
        }
      }
      Node ar = d_rewriter->rewrite(a);
      std::unordered_map<Node, Node>::iterator itr = acr.find(ar);
      if (itr != acr.end())
      {
        aMatch = itr->second;
      }
    }

    // if we found a match either by symmetry or rewriting, then we connect
    // the assumption here.
    if (!aMatch.isNull())
    {
      std::shared_ptr<ProofNode> pfaa = mkAssume(aMatch);
      // must correct the orientation on this leaf
      std::vector<std::shared_ptr<ProofNode>> children;
      children.push_back(pfaa);
      for (std::shared_ptr<ProofNode> pfs : fa.second)
      {
        Assert(pfs->getResult() == a);
        // use SYMM if possible
        if (aMatch == aeqSym)
        {
          if (pfaa->getRule() == PfRule::SYMM)
          {
            updateNode(pfs.get(), pfaa->getChildren()[0].get());
          }
          else
          {
            updateNode(pfs.get(), PfRule::SYMM, children, {});
          }
        }
        else
        {
          updateNode(pfs.get(), PfRule::MACRO_SR_PRED_TRANSFORM, children, {a});
        }
      }
      Trace("pnm-scope") << "...finished" << std::endl;
      acu.insert(aMatch);
      continue;
    }
    // If we did not find a match, it is an error, since all free assumptions
    // should be arguments to SCOPE.
    std::stringstream ss;

    bool dumpProofTraceOn = Trace.isOn("dump-proof-error");
    if (dumpProofTraceOn)
    {
      ss << "The proof : " << *pf << std::endl;
    }
    ss << std::endl << "Free assumption: " << a << std::endl;
    for (const Node& aprint : ac)
    {
      ss << "- assumption: " << aprint << std::endl;
    }
    if (!dumpProofTraceOn)
    {
      ss << "Use -t dump-proof-error for details on proof" << std::endl;
    }
    Unreachable() << "Generated a proof that is not closed by the scope: "
                  << ss.str() << std::endl;
  }
  if (acu.size() < ac.size())
  {
    // All assumptions should match a free assumption; if one does not, then
    // the explanation could have been smaller.
    for (const Node& a : ac)
    {
      if (acu.find(a) == acu.end())
      {
        Notice() << "ProofNodeManager::mkScope: assumption " << a
                 << " does not match a free assumption in proof" << std::endl;
      }
    }
  }
  if (doMinimize && acu.size() < ac.size())
  {
    assumps.clear();
    assumps.insert(assumps.end(), acu.begin(), acu.end());
  }
  else if (ac.size() < assumps.size())
  {
    // remove duplicates to avoid redundant literals in clauses
    assumps.clear();
    assumps.insert(assumps.end(), ac.begin(), ac.end());
  }
  Node minExpected;
  NodeManager* nm = NodeManager::currentNM();
  Node exp;
  if (assumps.empty())
  {
    // SCOPE with no arguments is a no-op, just return original
    return pf;
  }
  Node conc = pf->getResult();
  exp = assumps.size() == 1 ? assumps[0] : nm->mkNode(AND, assumps);
  if (conc.isConst() && !conc.getConst<bool>())
  {
    minExpected = exp.notNode();
  }
  else
  {
    minExpected = nm->mkNode(IMPLIES, exp, conc);
  }
  return mkNode(PfRule::SCOPE, {pf}, assumps, minExpected);
}

bool ProofNodeManager::updateNode(
    ProofNode* pn,
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args)
{
  return updateNodeInternal(pn, id, children, args, true);
}

bool ProofNodeManager::updateNode(ProofNode* pn, ProofNode* pnr)
{
  Assert(pn != nullptr);
  Assert(pnr != nullptr);
  if (pn == pnr)
  {
    // same node, no update necessary
    return true;
  }
  if (pn->getResult() != pnr->getResult())
  {
    return false;
  }
  // copy whether we did the check
  pn->d_provenChecked = pnr->d_provenChecked;
  // can shortcut re-check of rule
  return updateNodeInternal(
      pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
}

void ProofNodeManager::ensureChecked(ProofNode* pn)
{
  if (pn->d_provenChecked)
  {
    // already checked
    return;
  }
  // directly call the proof checker
  Node res = d_checker->check(pn, pn->getResult());
  pn->d_provenChecked = true;
  // should have the correct result
  Assert(res == pn->d_proven);
}

Node ProofNodeManager::checkInternal(
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    Node expected,
    bool& didCheck)
{
  // if the user supplied an expected result, then we trust it if we are in
  // a proof checking mode that does not eagerly check rule applications
  if (!expected.isNull())
  {
    if (options::proofCheck() == options::ProofCheckMode::LAZY
        || options::proofCheck() == options::ProofCheckMode::NONE)
    {
      return expected;
    }
  }
  // check with the checker, which takes expected as argument
  Node res = d_checker->check(id, children, args, expected);
  didCheck = true;
  Assert(!res.isNull())
      << "ProofNodeManager::checkInternal: failed to check proof";
  return res;
}

ProofChecker* ProofNodeManager::getChecker() const { return d_checker; }

std::shared_ptr<ProofNode> ProofNodeManager::clone(
    std::shared_ptr<ProofNode> pn) const
{
  const ProofNode* orig = pn.get();
  std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>> visited;
  std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>>::iterator it;
  std::vector<const ProofNode*> visit;
  std::shared_ptr<ProofNode> cloned;
  visit.push_back(orig);
  const ProofNode* cur;
  while (!visit.empty())
  {
    cur = visit.back();
    it = visited.find(cur);
    if (it == visited.end())
    {
      visited[cur] = nullptr;
      const std::vector<std::shared_ptr<ProofNode>>& children =
          cur->getChildren();
      for (const std::shared_ptr<ProofNode>& cp : children)
      {
        visit.push_back(cp.get());
      }
      continue;
    }
    visit.pop_back();
    if (it->second.get() == nullptr)
    {
      std::vector<std::shared_ptr<ProofNode>> cchildren;
      const std::vector<std::shared_ptr<ProofNode>>& children =
          cur->getChildren();
      for (const std::shared_ptr<ProofNode>& cp : children)
      {
        it = visited.find(cp.get());
        Assert(it != visited.end());
        // if we encounter nullptr here, then this child is currently being
        // traversed at a higher level, hence this corresponds to a cyclic
        // proof.
        if (it->second == nullptr)
        {
          Unreachable() << "Cyclic proof encountered when cloning a proof node";
        }
        cchildren.push_back(it->second);
      }
      cloned = std::make_shared<ProofNode>(
          cur->getRule(), cchildren, cur->getArguments());
      visited[cur] = cloned;
      // we trust the above cloning does not change what is proven
      cloned->d_proven = cur->d_proven;
      cloned->d_provenChecked = cur->d_provenChecked;
    }
  }
  Assert(visited.find(orig) != visited.end());
  return visited[orig];
}

ProofNode* ProofNodeManager::cancelDoubleSymm(ProofNode* pn)
{
  while (pn->getRule() == PfRule::SYMM)
  {
    std::shared_ptr<ProofNode> pnc = pn->getChildren()[0];
    if (pnc->getRule() == PfRule::SYMM)
    {
      pn = pnc->getChildren()[0].get();
    }
    else
    {
      break;
    }
  }
  return pn;
}

bool ProofNodeManager::updateNodeInternal(
    ProofNode* pn,
    PfRule id,
    const std::vector<std::shared_ptr<ProofNode>>& children,
    const std::vector<Node>& args,
    bool needsCheck)
{
  Assert(pn != nullptr);
  // ---------------- check for cyclic
  if (options::proofCheck() == options::ProofCheckMode::EAGER)
  {
    std::unordered_set<const ProofNode*> visited;
    for (const std::shared_ptr<ProofNode>& cpc : children)
    {
      if (expr::containsSubproof(cpc.get(), pn, visited))
      {
        std::stringstream ss;
        ss << "ProofNodeManager::updateNode: attempting to make cyclic proof! "
           << id << " " << pn->getResult() << ", children = " << std::endl;
        for (const std::shared_ptr<ProofNode>& cp : children)
        {
          ss << "  " << cp->getRule() << " " << cp->getResult() << std::endl;
        }
        ss << "Full children:" << std::endl;
        for (const std::shared_ptr<ProofNode>& cp : children)
        {
          ss << "  - ";
          cp->printDebug(ss);
          ss << std::endl;
        }
        Unreachable() << ss.str();
      }
    }
  }
  // ---------------- end check for cyclic

  // should have already computed what is proven
  Assert(!pn->d_proven.isNull())
      << "ProofNodeManager::updateProofNode: invalid proof provided";
  if (needsCheck)
  {
    // We expect to prove the same thing as before
    bool didCheck = false;
    Node res = checkInternal(id, children, args, pn->d_proven, didCheck);
    if (res.isNull())
    {
      // if it was invalid, then we do not update
      return false;
    }
    // proven field should already be the same as the result
    Assert(res == pn->d_proven);
    pn->d_provenChecked = didCheck;
  }

  // we update its value
  pn->setValue(id, children, args);
  return true;
}

}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Andrew Reynolds, Haniel Barbosa, Aina Niemetz
4		*
5		* This file is part of the cvc5 project.
6		*
7		* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
8		* in the top-level source directory and their institutional affiliations.
9		* All rights reserved. See the file COPYING in the top-level source
10		* directory for licensing information.
11		* ****************************************************************************
12		*
13		* Implementation of proof node manager.
14		*/
15
16		#include "proof/proof_node_manager.h"
17
18		#include <sstream>
19
20		#include "options/proof_options.h"
21		#include "proof/proof.h"
22		#include "proof/proof_checker.h"
23		#include "proof/proof_node.h"
24		#include "proof/proof_node_algorithm.h"
25		#include "theory/rewriter.h"
26
27		using namespace cvc5::kind;
28
29		namespace cvc5 {
30
31	7987	ProofNodeManager::ProofNodeManager(theory::Rewriter* rr, ProofChecker* pc)
32	7987	: d_rewriter(rr), d_checker(pc)
33		{
34	7987	d_true = NodeManager::currentNM()->mkConst(true);
35		// we always allocate a proof checker, regardless of the proof checking mode
36	7987	Assert(d_checker != nullptr);
37	7987	}
38
39	19019241	std::shared_ptr<ProofNode> ProofNodeManager::mkNode(
40		PfRule id,
41		const std::vector<std::shared_ptr<ProofNode>>& children,
42		const std::vector<Node>& args,
43		Node expected)
44		{
45	38038482	Trace("pnm") << "ProofNodeManager::mkNode " << id << " {" << expected.getId()
46	19019241	<< "} " << expected << "\n";
47	19019241	bool didCheck = false;
48	38038482	Node res = checkInternal(id, children, args, expected, didCheck);
49	19019241	if (res.isNull())
50		{
51		// if it was invalid, then we return the null node
52		return nullptr;
53		}
54		// otherwise construct the proof node and set its proven field
55		std::shared_ptr<ProofNode> pn =
56	38038482	std::make_shared<ProofNode>(id, children, args);
57	19019241	pn->d_proven = res;
58	19019241	pn->d_provenChecked = didCheck;
59	19019241	return pn;
60		}
61
62	9968200	std::shared_ptr<ProofNode> ProofNodeManager::mkAssume(Node fact)
63		{
64	9968200	Assert(!fact.isNull());
65	9968200	Assert(fact.getType().isBoolean());
66	9968200	return mkNode(PfRule::ASSUME, {}, {fact}, fact);
67		}
68
69	329886	std::shared_ptr<ProofNode> ProofNodeManager::mkSymm(
70		std::shared_ptr<ProofNode> child, Node expected)
71		{
72	329886	if (child->getRule() == PfRule::SYMM)
73		{
74	203	Assert(expected.isNull()
75		\|\| child->getChildren()[0]->getResult() == expected);
76	203	return child->getChildren()[0];
77		}
78	329683	return mkNode(PfRule::SYMM, {child}, {}, expected);
79		}
80
81	392	std::shared_ptr<ProofNode> ProofNodeManager::mkTrans(
82		const std::vector<std::shared_ptr<ProofNode>>& children, Node expected)
83		{
84	392	Assert(!children.empty());
85	392	if (children.size() == 1)
86		{
87		Assert(expected.isNull() \|\| children[0]->getResult() == expected);
88		return children[0];
89		}
90	392	return mkNode(PfRule::TRANS, children, {}, expected);
91		}
92
93	191455	std::shared_ptr<ProofNode> ProofNodeManager::mkScope(
94		std::shared_ptr<ProofNode> pf,
95		std::vector<Node>& assumps,
96		bool ensureClosed,
97		bool doMinimize,
98		Node expected)
99		{
100	191455	if (!ensureClosed)
101		{
102	57287	return mkNode(PfRule::SCOPE, {pf}, assumps, expected);
103		}
104	134168	Trace("pnm-scope") << "ProofNodeManager::mkScope " << assumps << std::endl;
105		// we first ensure the assumptions are flattened
106	268336	std::unordered_set<Node> ac{assumps.begin(), assumps.end()};
107		// map from the rewritten form of assumptions to the original. This is only
108		// computed in the rare case when we need rewriting to match the
109		// assumptions. An example of this is for Boolean constant equalities in
110		// scoped proofs from the proof equality engine.
111	268336	std::unordered_map<Node, Node> acr;
112		// whether we have compute the map above
113	134168	bool computedAcr = false;
114
115		// The free assumptions of the proof
116	268336	std::map<Node, std::vector<std::shared_ptr<ProofNode>>> famap;
117	134168	expr::getFreeAssumptionsMap(pf, famap);
118	268336	std::unordered_set<Node> acu;
119	565760	for (const std::pair<const Node, std::vector<std::shared_ptr<ProofNode>>>&
120	134168	fa : famap)
121		{
122	1131520	Node a = fa.first;
123	1008254	if (ac.find(a) != ac.end())
124		{
125		// already covered by an assumption
126	442494	acu.insert(a);
127	442494	continue;
128		}
129		// trivial assumption
130	123266	if (a == d_true)
131		{
132		Trace("pnm-scope") << "- justify trivial True assumption\n";
133		for (std::shared_ptr<ProofNode> pfs : fa.second)
134		{
135		Assert(pfs->getResult() == a);
136		updateNode(pfs.get(), PfRule::MACRO_SR_PRED_INTRO, {}, {a});
137		}
138		Trace("pnm-scope") << "...finished" << std::endl;
139		acu.insert(a);
140		continue;
141		}
142	123266	Trace("pnm-scope") << "- try matching free assumption " << a << "\n";
143		// otherwise it may be due to symmetry?
144	246532	Node aeqSym = CDProof::getSymmFact(a);
145	123266	Trace("pnm-scope") << " - try sym " << aeqSym << "\n";
146	246532	Node aMatch;
147	123266	if (!aeqSym.isNull() && ac.count(aeqSym))
148		{
149	245298	Trace("pnm-scope") << "- reorient assumption " << aeqSym << " via " << a
150	245298	<< " for " << fa.second.size() << " proof nodes"
151	122649	<< std::endl;
152	122649	aMatch = aeqSym;
153		}
154		else
155		{
156		// Otherwise, may be derivable by rewriting. Note this is used in
157		// ensuring that proofs from the proof equality engine that involve
158		// equality with Boolean constants are closed.
159	617	if (!computedAcr)
160		{
161	243	computedAcr = true;
162	3508	for (const Node& acc : ac)
163		{
164	6530	Node accr = d_rewriter->rewrite(acc);
165	3265	if (accr != acc)
166		{
167	1262	acr[accr] = acc;
168		}
169		}
170		}
171	1234	Node ar = d_rewriter->rewrite(a);
172	617	std::unordered_map<Node, Node>::iterator itr = acr.find(ar);
173	617	if (itr != acr.end())
174		{
175	617	aMatch = itr->second;
176		}
177		}
178
179		// if we found a match either by symmetry or rewriting, then we connect
180		// the assumption here.
181	123266	if (!aMatch.isNull())
182		{
183	246532	std::shared_ptr<ProofNode> pfaa = mkAssume(aMatch);
184		// must correct the orientation on this leaf
185	246532	std::vector<std::shared_ptr<ProofNode>> children;
186	123266	children.push_back(pfaa);
187	246532	for (std::shared_ptr<ProofNode> pfs : fa.second)
188		{
189	123266	Assert(pfs->getResult() == a);
190		// use SYMM if possible
191	123266	if (aMatch == aeqSym)
192		{
193	122649	if (pfaa->getRule() == PfRule::SYMM)
194		{
195		updateNode(pfs.get(), pfaa->getChildren()[0].get());
196		}
197		else
198		{
199	122649	updateNode(pfs.get(), PfRule::SYMM, children, {});
200		}
201		}
202		else
203		{
204	617	updateNode(pfs.get(), PfRule::MACRO_SR_PRED_TRANSFORM, children, {a});
205		}
206		}
207	123266	Trace("pnm-scope") << "...finished" << std::endl;
208	123266	acu.insert(aMatch);
209	123266	continue;
210		}
211		// If we did not find a match, it is an error, since all free assumptions
212		// should be arguments to SCOPE.
213		std::stringstream ss;
214
215		bool dumpProofTraceOn = Trace.isOn("dump-proof-error");
216		if (dumpProofTraceOn)
217		{
218		ss << "The proof : " << *pf << std::endl;
219		}
220		ss << std::endl << "Free assumption: " << a << std::endl;
221		for (const Node& aprint : ac)
222		{
223		ss << "- assumption: " << aprint << std::endl;
224		}
225		if (!dumpProofTraceOn)
226		{
227		ss << "Use -t dump-proof-error for details on proof" << std::endl;
228		}
229		Unreachable() << "Generated a proof that is not closed by the scope: "
230		<< ss.str() << std::endl;
231		}
232	134168	if (acu.size() < ac.size())
233		{
234		// All assumptions should match a free assumption; if one does not, then
235		// the explanation could have been smaller.
236	47418	for (const Node& a : ac)
237		{
238	43134	if (acu.find(a) == acu.end())
239		{
240	28735	Notice() << "ProofNodeManager::mkScope: assumption " << a
241		<< " does not match a free assumption in proof" << std::endl;
242		}
243		}
244		}
245	134168	if (doMinimize && acu.size() < ac.size())
246		{
247	3240	assumps.clear();
248	3240	assumps.insert(assumps.end(), acu.begin(), acu.end());
249		}
250	130928	else if (ac.size() < assumps.size())
251		{
252		// remove duplicates to avoid redundant literals in clauses
253	715	assumps.clear();
254	715	assumps.insert(assumps.end(), ac.begin(), ac.end());
255		}
256	268336	Node minExpected;
257	134168	NodeManager* nm = NodeManager::currentNM();
258	268336	Node exp;
259	134168	if (assumps.empty())
260		{
261		// SCOPE with no arguments is a no-op, just return original
262	2540	return pf;
263		}
264	263256	Node conc = pf->getResult();
265	131628	exp = assumps.size() == 1 ? assumps[0] : nm->mkNode(AND, assumps);
266	131628	if (conc.isConst() && !conc.getConst<bool>())
267		{
268	48625	minExpected = exp.notNode();
269		}
270		else
271		{
272	83003	minExpected = nm->mkNode(IMPLIES, exp, conc);
273		}
274	131628	return mkNode(PfRule::SCOPE, {pf}, assumps, minExpected);
275		}
276
277	194045	bool ProofNodeManager::updateNode(
278		ProofNode* pn,
279		PfRule id,
280		const std::vector<std::shared_ptr<ProofNode>>& children,
281		const std::vector<Node>& args)
282		{
283	194045	return updateNodeInternal(pn, id, children, args, true);
284		}
285
286	2265550	bool ProofNodeManager::updateNode(ProofNode* pn, ProofNode* pnr)
287		{
288	2265550	Assert(pn != nullptr);
289	2265550	Assert(pnr != nullptr);
290	2265550	if (pn == pnr)
291		{
292		// same node, no update necessary
293	2187	return true;
294		}
295	2263363	if (pn->getResult() != pnr->getResult())
296		{
297		return false;
298		}
299		// copy whether we did the check
300	2263363	pn->d_provenChecked = pnr->d_provenChecked;
301		// can shortcut re-check of rule
302	2263363	return updateNodeInternal(
303	2263363	pn, pnr->getRule(), pnr->getChildren(), pnr->getArguments(), false);
304		}
305
306	2533315	void ProofNodeManager::ensureChecked(ProofNode* pn)
307		{
308	2533315	if (pn->d_provenChecked)
309		{
310		// already checked
311	114098	return;
312		}
313		// directly call the proof checker
314	4838434	Node res = d_checker->check(pn, pn->getResult());
315	2419217	pn->d_provenChecked = true;
316		// should have the correct result
317	2419217	Assert(res == pn->d_proven);
318		}
319
320	19213286	Node ProofNodeManager::checkInternal(
321		PfRule id,
322		const std::vector<std::shared_ptr<ProofNode>>& children,
323		const std::vector<Node>& args,
324		Node expected,
325		bool& didCheck)
326		{
327		// if the user supplied an expected result, then we trust it if we are in
328		// a proof checking mode that does not eagerly check rule applications
329	19213286	if (!expected.isNull())
330		{
331	36197076	if (options::proofCheck() == options::ProofCheckMode::LAZY
332	18098538	\|\| options::proofCheck() == options::ProofCheckMode::NONE)
333		{
334	18095950	return expected;
335		}
336		}
337		// check with the checker, which takes expected as argument
338	2234672	Node res = d_checker->check(id, children, args, expected);
339	1117336	didCheck = true;
340	1117336	Assert(!res.isNull())
341		<< "ProofNodeManager::checkInternal: failed to check proof";
342	1117336	return res;
343		}
344
345	11024014	ProofChecker* ProofNodeManager::getChecker() const { return d_checker; }
346
347	60736	std::shared_ptr<ProofNode> ProofNodeManager::clone(
348		std::shared_ptr<ProofNode> pn) const
349		{
350	60736	const ProofNode* orig = pn.get();
351	121472	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>> visited;
352	60736	std::unordered_map<const ProofNode*, std::shared_ptr<ProofNode>>::iterator it;
353	121472	std::vector<const ProofNode*> visit;
354	121472	std::shared_ptr<ProofNode> cloned;
355	60736	visit.push_back(orig);
356		const ProofNode* cur;
357	3948056	while (!visit.empty())
358		{
359	1943660	cur = visit.back();
360	1943660	it = visited.find(cur);
361	1943660	if (it == visited.end())
362		{
363	905092	visited[cur] = nullptr;
364		const std::vector<std::shared_ptr<ProofNode>>& children =
365	905092	cur->getChildren();
366	1882924	for (const std::shared_ptr<ProofNode>& cp : children)
367		{
368	977832	visit.push_back(cp.get());
369		}
370	905092	continue;
371		}
372	1038568	visit.pop_back();
373	1038568	if (it->second.get() == nullptr)
374		{
375	1810184	std::vector<std::shared_ptr<ProofNode>> cchildren;
376		const std::vector<std::shared_ptr<ProofNode>>& children =
377	905092	cur->getChildren();
378	1882924	for (const std::shared_ptr<ProofNode>& cp : children)
379		{
380	977832	it = visited.find(cp.get());
381	977832	Assert(it != visited.end());
382		// if we encounter nullptr here, then this child is currently being
383		// traversed at a higher level, hence this corresponds to a cyclic
384		// proof.
385	977832	if (it->second == nullptr)
386		{
387		Unreachable() << "Cyclic proof encountered when cloning a proof node";
388		}
389	977832	cchildren.push_back(it->second);
390		}
391	1810184	cloned = std::make_shared<ProofNode>(
392	1810184	cur->getRule(), cchildren, cur->getArguments());
393	905092	visited[cur] = cloned;
394		// we trust the above cloning does not change what is proven
395	905092	cloned->d_proven = cur->d_proven;
396	905092	cloned->d_provenChecked = cur->d_provenChecked;
397		}
398		}
399	60736	Assert(visited.find(orig) != visited.end());
400	121472	return visited[orig];
401		}
402
403	268905	ProofNode* ProofNodeManager::cancelDoubleSymm(ProofNode* pn)
404		{
405	269993	while (pn->getRule() == PfRule::SYMM)
406		{
407	268905	std::shared_ptr<ProofNode> pnc = pn->getChildren()[0];
408	267817	if (pnc->getRule() == PfRule::SYMM)
409		{
410	1088	pn = pnc->getChildren()[0].get();
411		}
412		else
413		{
414	266729	break;
415		}
416		}
417	267817	return pn;
418		}
419
420	2457408	bool ProofNodeManager::updateNodeInternal(
421		ProofNode* pn,
422		PfRule id,
423		const std::vector<std::shared_ptr<ProofNode>>& children,
424		const std::vector<Node>& args,
425		bool needsCheck)
426		{
427	2457408	Assert(pn != nullptr);
428		// ---------------- check for cyclic
429	2457408	if (options::proofCheck() == options::ProofCheckMode::EAGER)
430		{
431	784	std::unordered_set<const ProofNode*> visited;
432	494	for (const std::shared_ptr<ProofNode>& cpc : children)
433		{
434	102	if (expr::containsSubproof(cpc.get(), pn, visited))
435		{
436		std::stringstream ss;
437		ss << "ProofNodeManager::updateNode: attempting to make cyclic proof! "
438		<< id << " " << pn->getResult() << ", children = " << std::endl;
439		for (const std::shared_ptr<ProofNode>& cp : children)
440		{
441		ss << " " << cp->getRule() << " " << cp->getResult() << std::endl;
442		}
443		ss << "Full children:" << std::endl;
444		for (const std::shared_ptr<ProofNode>& cp : children)
445		{
446		ss << " - ";
447		cp->printDebug(ss);
448		ss << std::endl;
449		}
450		Unreachable() << ss.str();
451		}
452		}
453		}
454		// ---------------- end check for cyclic
455
456		// should have already computed what is proven
457	2457408	Assert(!pn->d_proven.isNull())
458		<< "ProofNodeManager::updateProofNode: invalid proof provided";
459	2457408	if (needsCheck)
460		{
461		// We expect to prove the same thing as before
462	194045	bool didCheck = false;
463	388090	Node res = checkInternal(id, children, args, pn->d_proven, didCheck);
464	194045	if (res.isNull())
465		{
466		// if it was invalid, then we do not update
467		return false;
468		}
469		// proven field should already be the same as the result
470	194045	Assert(res == pn->d_proven);
471	194045	pn->d_provenChecked = didCheck;
472		}
473
474		// we update its value
475	2457408	pn->setValue(id, children, args);
476	2457408	return true;
477		}
478
479	31125	} // namespace cvc5